1. Field of the Invention
The present invention relates generally to a card connector, and more specifically to a card connector with two-stage ejection mechanism and card-retaining mechanism, a memory card can be stably and reliably retained in the card connector.
2. The Related Art
Nowadays, with the development of Personal Computer and the related electronic products, many kinds of memory cards are widely applied, such as PCMCIA (Personal Computer Memory Card International Association) card, SD (Secure Digital) card and CF (Compact Flash) card. Accordingly, card connectors applied in such products appear. Especially, the card connector with two-stage ejection mechanism and card-retaining mechanism is widely applied.
U.S. Pat. No. 6,537,090 discloses a card connector with two-stage ejection mechanism and card-retaining mechanism. The card connector comprises a case cover, a plastic case for engagement with the case cover, a card detachable mechanism and a card-retaining mechanism. The card detachable mechanism and the card-retaining mechanism are installed between the case cover and the plastic case.
The card detachable mechanism disclosed in U.S. Pat. No. 6,537,090 comprises a repositioning spring, a slider, a pin member and a heart-shaped cam groove. The repositioning spring is clamped between the slider and the plastic case. The slider is smoothly engaged with one side of the plastic case. The heart-shaped cam groove is formed on the plastic case. One end of the pin member for engagement with the slider and the other end of the pin member is put into the heart-shaped cam groove. The other end of the pin member moves back and forth along the heart-shaped the heart-shaped cam groove.
The card-retaining mechanism has a pin support embedded in the slider. The pin support has a J-shaped engaging projection at the rear for engagement with a groove formed on a memory card. According to the J-shaped engaging projection of the pin support, a corresponding groove is formed on the slider in order to supply enough space for the J-shaped engaging projection to metamorphose under the pressure of card. The pin support further flexes a pressing support for engagement with the pin member, so that the pin member would not release engagement with the heart-shaped cam groove due to upward movement when it reciprocates in the heart-shaped cam groove.
When operating, firstly, the memory card is put into the front of card-inserting space formed between the case cover and the plastic case. Then, the memory card is put to move forward as the first section operation. At the same time, the memory card is pushed to the memory card retaining position at the back of the card-insertion space by means of reciprocation of the pin member. Simultaneously the memory card is fixedly located in the card-insertion space by the engagement between the J-shaped engaging projection of the pin support and the notch of the memory card. During the second period of pushing memory card forwardly, the memory card is ejected backward from the card retaining position through the reciprocation movement of the pin member and the elasticity of the spring. In the mean while, the J-shaped engaging projection of the pin support deforms elastically to the slider under the pressure of the card, and then gets out from the groove of the card. Then, the engagement between the memory card and the card connector is released. In the end, the memory is taken out from the card-insertion space without any effort.
In the above-mentioned card connector, however, the pin support and the slider are respectively prepared and then assembled. It is difficult to satisfy the need to make a card connector compact and light-weight. Furthermore, only depending on the elasticity of the pin support to engage a notch of the memory card with the J-shaped engaging projection for retaining would cause the memory card to be drawn out from the card connector easily, but to be retained therein difficultly.
U.S. Pat. No. 6,537,090 discloses another card connector with two-stage card ejection mechanism and card-retaining mechanism. The card connector has a guiding portion set on the plastic case body. When a memory card is inserted, a guiding pin guides a retaining elastic pin to slide along. When the retaining elastic pin is elastically deformed, a hook formed at the free end of the retaining elastic pin stretches into a groove on one side of a memory card, so that the memory card is retained in a card inserting space. When the retaining elastic pin restores elasticity, the hook retracts from a groove of the memory card, accordingly, to release the engagement between the memory card and the card connector. When the memory card is repeatedly inserted and extracted by means of the persistent propping of the guiding portion, although the memory card can be reliably retained in the card connector, the stress on the back of the retaining elastic pin connected with the slider is intensive. Additionally, the retaining elastic pin is easy to be distorted due to fatigue, even to release the engagement with the slider, because the retaining elastic pin is separately formed with the slider as a whole.
In addition, the pressing elastic pin used to confine the pin member is not designed as a whole. One pressing elastic pin is cut from the top of the shielding case cover corresponding to the member pin, or a pressing portion is extended from the front of the plastic slider, in order to confine the pin member, accordingly, it is difficult to leave the heart-shaped cam groove. The pressing elastic pin is formed on the top of the shielding case cover. The design makes the slider, the retaining elastic pin and the pressing elastic pin formed respectively. It is difficult to make the card connector compact and light-weight. A pressing portion is extended from the front of the plastic slider, so that it cannot make the card connector compact and light-weight enough due to too large volume. Furthermore, because the engagement between the pressing portion and the pin member is inelastic, it is easy for the pressing portion to release the engagement for the pin member and become ineffective due to fatigue.
Another card connector with tow-stage ejection mechanism and card-retaining mechanism is disclosed in U.S. Pat. No. 6,729,892. A guiding groove is set on one side of the top plain of a shielding case cover, which is another kind of design. A guiding groove extends in the card inserting direction with the width of the guiding groove increasing. The guiding groove comprises a straight border and a flexural border. The straight border is near to a side board of a shielding case cover. The flexural border is far away from the side board. The distance between the front of the flexural border and the side board is smaller than the distance between the back of the flexural border and the side board. Accordingly, a retaining elastic pin is guided to prop along the flexural border. When the retaining elastic pin is not deformed elastically, a memory card is retained in a card inserting space. When the retaining elastic pin is deformed elastically, the memory card is extracted from the card connector. The retaining portion is horizontal to the wide end of a guiding groove. A hook at the end of the retaining elastic pin has enough space to move back along the wide end of the guiding groove, when the retaining elastic pin moves relatively to the memory card due to unexpected circumstances. Accordingly, the retaining elastic pin releases the engagement with the groove of the memory card to make the memory card difficult to be reliably retained. Furthermore, it is possible for the retaining elastic pin to release the engagement with the slider and difficult to make the card connector compact and light-weight.